Weight indicator and drilling line anchor



Nov. 15, 1949 J. D. SPALDING WEIGHT INDICATOR AND DRILLING LINE ANCHOR Filed Jan. 15, 1945 Patenta! Nov. 15, 19 49 fasao'o wmGn'r smca'roa AND DBILLING LINE .menon John D. splding, Los Angeles, Calii'., assigor to v v The National Supply Company, Pittbrgh, Pa.,

a oorporation ot Pennylvania Application' January 15, 1945, Serial No. 572,835

9 Clain. (01.73-143) This invention relates to weight indicators and is more particularly directed to a device !or anchoring the dead end of 'a hoisting line or cable and indicating the line pull imposed upon the line or cable.

In rotary drilling operations it is desirable to know the load or weight being imposed upon the drill bit. This load is usually determined' by measuring the total` Suspended weight of the drill string, and then lowering the drill string until the drill bit rests on bottom and supports a part of the drill string weight. The reduction in amount of Suspended weight represents the weight imposed on the bit. The total drill string load on the supporting hook is determined by measuring the tension in the cable or hoisting line that suspends the hook in the derrick. With this knowledge of the load carried by the supporting hook, the driller is enabled to determine the pressure at which the drilling bit is working and to adjust the load to either increase or decrease the pressure as required to obtain maximum drilling emciency and to avoid overloading which may and many times does result in twist-0115."

In the patent issued to Edward Timbs, No.

2,282,685, May 12, 1942, for Cable anchor, there is disclosed a tie-down for the dead end of a drilling line or cable which enables a direct line pull to be imposed upon a snubbing drum without imposition of objectional stresses upon the cable clamping means.

It is the object of this invention to improve this former cable anchor and to utilize the advantageous features thereof in combination with an indicating means Operating from the snubbing drum to indicate the cable pull or load at the dead end of the drilling line or cable.

Another object of this invention is to provide a weight indicating device operative while utilizing the torque on a cable dead end anchor to indicate the line pull.

Another object of this invention is to provide a combined dead end line anchor and weight indicator wherein the line is wound upon a snubbing drum and the torque thus imparted to the snubbing drum is transmitted to the hydraulic fluid in a cylinder to be registered in a gauge calibrated to read directly the load carried by the supporting element or hook which is supported between the ends of the said cable.

Other objects and advantages of the invention it is believed will be apparent from the hereinafter set !orth description of a preferred embodiment of my invention as illustrated in the accompanying drawings.

In the drawings:

Figura 1 is a diagrammatic view of a weight in'- icator and cable tie-down embodying my inven- Figure 2 is a sectional view taken substantially on the line 2-2 of Figur-e 1.

Flgure 3 is a sectional view taken substantially on the line 3--3 of Figure 2.

In the preferred embodiment of my invention as illustrated in the accompanying drawing, I indicates a line which is normally a cable and passes over the crown block of a drilling rig and is reeved between the sheaves of such block and the sheav'es of a traveling block and has its live end wound' upon the reel of a hoist called a drawworks drum. In this practice the traveling block commonly carries a connecting element or hook to which the "drilling" string or pipe is Suspended. A drilling bit is carried at the bottom of the pipe and forms the well hole as the pipe is rotated and the pressure or load imposed upon the said bit is regulated by the driller. This load is determined by the driller Operating the drawworks drum to lift the drill pipe so that only a part of the pipe weight forms the load on the bit. The foregoing is common drilling procedure and therefore the specific elements of the drllling rig are not illustrated. I

The dead end of the line l is suitably anchored in the drilling rig and for this purpose I employ an anchor which is patterned after the anchor of the Timbs Patent No. 2281685, modified to incorporate a weight indicating means therein with the minimum of additional parts. Thus the anchor device includes a frame or footing 2 which is Secured to the derrick or rig and to the concrete foundation thereof by means of anchorin 'bolts 3. i

A snubbing drum 4 or anchoring element is supported by the footing 2 through the medium of a standard 5, bearings 6 and shaft 1. The shaft 'I is press-fltted into the hub 8 of the drum 4 and is journaled upon the bearlngs 6.

The snubbing drum 4 is formed with marginal fianges 9 and o deflning the snubbing surface i I upon which the table I is wound. The drum 4 is also formed with an integral pressure arm i! which extends downwardly and outwardly from its lower surface and upon which the cable l is clamped. u

The cable clamp IS may be oi' any desired form and is herein indicated as including a clamp base !4 formed with the arm |2 and having a cap II which is hinged to the base |4 and is adapted to be held down by means ora pair ot eye bolts &433.070

^ Interposed between the cap II and the block !4 s iormed upon the standard! to engage a compementary stop section of the drum 4. A stop screw 2| may be threaded into the stop section s to provide an adiustment oi the limitet angular travel oi the drum 4.

A spring 22 is connected between the arm !2 and standard I to avoid free rotation ot the drum 4 in a direction opposite to the arrow 23. This spring 22 is connected by means oi its attachment-bol 24 to the web 25 of the arm |2 so as to permit ted freedom oi' movement without spring res stance thereto.

Means are provided i'or applying the torque transmitted to the arm |2 by the drum 4 in a direct line to the piston 28. As herein illustrated; this means' includes a ba1 2'| which is piston 26. The ball 21 is'engaged by a pressure root 29 formed upon the under surface of the arm l2. A line thrust is imparted from the arm l2 to the piston 26. As the ball 21 is tree to* revoive inthe enlarged cavity 28, it is desirable to prevent foreign 'matter from lodging in the cavity; ior this purpose a rubber or other fiexible hood 30 is snapped onto the foot 29 to engage the upper end of the piston 28 and house the ball 21. The piston 26 is mounted within a hydraulic cylinder Il supported upon the footing 2. suitable hydraulic packing 32 is positioned between the piston and cylinder wall. A shroud 33 is carried by 'the piston 26 and telescopes over the cylinder si to prevent foreign matter !rom lodging between the piston and cylinder.

The hydraulic cylinder 3! is connected with a hydraulic fluid line 24 which leads to a pressure gauge 35 which may be suitably calibrated to' indicate directly the weight in pounds which is suspended from the hook (not shown) supported by the cable i. connected in the line 34 is indicated a hydraulic fluid reservoir 36 suitably controlled by valves 31 and 38. A pump 39 may be positioned between the reservoir 36 and line 34 to provide tor initial cylinder pressure within the range desired in the cylinder l.

As set iorth in the Timbs Patent No. 2,282,685, the dead end .of the line or cable I is commonly wound upon a reel 40 to enable a renewal of the cabie portions which are continuously reaved'between the crown and traveling biocks. The clamp provided between the cap I! and base |4 is easily releasabe to permit this rewinding and the paying out of new cable when desired from the, reel 40 without in any way disrupting the weight in dicating means.

.Having iuly described my invention, it u to be understood that I do not wish to be limited to the details herein set Iorth, but my invention is o! the full scope oi the appended claims.

I claim:

1. In a cable anchor device of the class described. the Vcombination oi' an anchor footing, a snubbing drum pivotally supported thereby and adapted to receive a puralityoi loops of the cable,

. a pressure arm tixediy secured to the snubbin drum, releasabe clamping means on the pressure arm adapted to secure the cable thereto, a piston, means for operatively transmitting toi-que through said arm. rrom snubbing drum to the piston. a cylinder in which the piston is mounted and means connected with the cylinder !or indicating the iorce transmitted to the piston.

2. In a device 'oi the class described' tor anchoring and indicating the line pull on the deae end of a hoisting line, the combination oi! a footing, a snubbing drum pivotally supported by the iooting and provided with a drum surface adapted to receive a piurality ot loops ot the line, e pressure arm operatively connected with the snubbing drum, a piston positioned to be engagec by the pressure arm, a cylinder within which the piston is mounted, gauge means connected witt the cylinder to indicate the line pun transmittee' by the pressure arm to the piston, and meam remote from the drum surface for clamping the 'seated in a cavity 28 iormed at the end of the p cabe to the pressure arm.

3. In a device of the class described for anchoring and indicating the line pull on the dead end of a hoisting line, the combination of a footing. a snubbing drum pivotally supported by the tooting and provided with a drum surface adaptee to receive a plurality' of loops ot the line, a pressure arm operatively connected with the snut bing drum, a piston positioned to be engaged b: the pressure arm, a cylinder within which the piston is mounted, gauge means connected with the v cylinder to indicate the line pull transmitted b:

the pressure arm to the piston, means remote from the drum surface for clamping the cabl to the pressure arm, and means for limiting th pivotal movement of the snubbing drum relative to the iootin's. v

4. In a device o! the class described for anchoring and indicating the line pull on the deae end ot a hoisting line, the combination of a iooting, a snubbing drum pivotally supported b: the footing and provided with a drum surface adapted to receive a plurality oi loops of the line a pressure arm Secured to the snubbing drum, releasable clamping means remote from the drun'. surface adapted to secure the line relative to the snubbing drum, a piston positioned to be engagec' by the pressure arm. a cylinder within which the piston is mounted. gauge means connected with the cylinder to indicate the line pull transmitted by the pressure arm to the piston,'and spring means mounted between the !ooting and the pressure arm to resist pivotal movement of the snubbing drum and the pressure arm in a direction opposite to that caused by the line pull.

5. In a device oi! the class described for anchoring and indicating theline pull on the dead end of a hoisti-ng line, the combination of a footing, a snubbing drum pivotally supported by the tooting, a pressure arm operatively connected with the snubbing drum, a piston positioned tc be engaged by the pressure arm, a cylinder within cylindrical snubbing drum surface disposed tangentially to the direction of the cable pull and of suflicient width to receive a plurality of loops of cable, means for pivotally connecting said ele ments for pivotal movement of said anchoring element about an axis, means operatively associated with said elements for measuring the cable pull as a function of the turning moment on said anchoring element about said axis, and releasable clamping means for said cable carried by said anchoring element at a position remote from the snubbing drum surface and from the load carrying portion of the cable, said clamping means having engaging portions positioned around the periphery of the cable and being releasable to provide for feeding of said cable through said clamping means.

7. In a device of the class described, the combination of a stationary element, a. cable anchoring element for a cable having a load thereon, said anchoring element having a substantially cylindrical snubbing drum surface disposed tangentially to the direction of the cable pull and of sufiicient width to receive a plurality of loops of cable. means 'for pivotally connecting said elements for pivotal movement of said anchoring element about an axis, means operatively associated with said elements for measuring the cable pull as a function of the turning moment on said anchoring element about said axis, said anchoring element having an arm extending outwardly from said axis, and releasable clamping means for said cable carried by said arm at a position remote from the snubbing drum surface and from the load carrying portion of the cable, said clamping means having engaging portions positioned around the periphery of the cable and being releasable to provide for feeding of said cable through said clamping means.

8. In a cable anchoring device, the combination of a stationary element, a non-rotary cable anchoring element for a cable having a load thereon, said anchoring element having a. snubbing drum surface disposed tangentially of the direction of the cable pull and of sufiicient width to receive a plurality of loops of the cable, pivotal means for connecting said elements for pivotal movement of said anchoring element about an axis, releasable clamping means for said cable carried by the anchoring element at a position remote from the snubbing drum surface and from the load carrying portion of the cable. said clamping' means having engaging portions positioned around the periphery of the cable and being releasable to provide tor feeding of said cable through said clamping means, and hydraulic means associated with said elements for measuring the cable pull as a function of the tuming moment on said anchoring element about said axis.

9. In a well drilling apparatus, a device for anchoring the deadend of a load carrying hoisting cable supporting a drilling string and for indicating the pull upon said cable while providing for readily feeding additional hoisting cable through said device from a cable supply source, said device comprising, a stationary frame, a cable anchoring structure mounted upon said frame for limited pivotal movement about an axis, said anchoring structure including a snubbing drum having a substantially cylindrical snubbing surface disposed tangentially to the direction of cable pull thereon and of sufiicient width to receive a plurality of loops of said cable, a cable clamping means carried by said cable anchoring structure at a position remote from said snubbing surface and remote from the load carrying portion of said cable. said clamping means having engaging portion positioned around the periphery of said cable and being releasable to provide for feeding of cable from said cable supply source through said clamping means, and means operatively associated with said cable anchoring structure and said frame for measuring the pull upon said cable as a function of the turning moment of said anchoring structure about said axis.

u JOHN D. SPALDING.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,692,057 Smith et al. Nov. 20, 1928 1,991,826 Taylor i Feb. 19, 1935 1,995,996 Moore Mar. 26, 1935 2,022,203 Hughes Nov. 26, 1935 2,024,147 Curtiss Dec. 17, 1935 2,025,928 Wunsch Dec. 31, 1935 2,079,021 Malcolm et al. May 4, 1937 2,187,345 Dinzl Jan. 16, 1940 2,210,759 Hansen Aug. 6, 1940 2,282.685 Timbs May 12, 1942 2,352,934 Bohannan July 4, 1944 2392302 Saunders Jan. 8, 1946 FOREIGN PATENTS Number Country Date Germany Oct. 20, 1924 

